The new 15W wireless battery-charger transmitter STWBC-MC from STMicroelectronics can control multiple charging coils, making charging less dependent on the precise position of the battery-powered device.
STWBC-MC is compliant with the latest Qi® 1.2.4 specification, and designed specifically to support the Qi MP-A15 EPP (Extended Power Profile) topology. In addition to detecting a valid receiver and selecting the most efficient coil for power transfer, it ensures extended Foreign Object Detection (FOD) through bi-directional communication with the receiver. Moreover, it also supports the proprietary wireless fast-charge extensions of leading smartphone manufacturers.
The STWBC-MC wireless battery-charger transmitter monitors coil current and voltage to ensure fast and stable charging for various types of devices. In addition, it integrates a digital DC-DC controlle to deliver the required power to the coil at a fixed frequency and thus minimizes interference with other systems inside smartphones and tablets. Given the EU’s intention to extend the scope of the Radio Equipment Directive (RED) to include wireless-charging transmitters, and restrict H-field emissions above 145kHz to -5dBm, the STWBC-MC’s low-EMI design eases compliance.
ST’s patented triple-path modulation technique for communication between the transmitter and receiver increases noise immunity and the IC’s low standby consumption minimizes wasted energy when not charging.
The STEVAL-ISB047V1 evaluation kit for the STWBC-MC and the STSW-STWBCGUI graphical user interface for ST’s STWBC transmitter ICs, allow a quick prototype development. The GUI can be used to download the STSW-ISB047FW dedicated firmware for the STWBC-MC, and to monitor performance and fine-tune parameters.
The STWBC-MC is currently in production, priced from $3.375 for orders of 1000 pieces. The STEVAL-ISB047V1 is available now from st.com or distributors, for $170.